2d advective-dispersive analytical modeling for the injection of produced waters from carbonate oil & gas fields in shallow coastal karst salinized aquifer.

Abstract

Geochemical compatibility between groundwater terrestrial of shallow coastal salinized karst aquifers of the north of Cuba, and produced waters of oil & gas carbonate fields was developed by Molerio (2015) based on the Pitzer´s Theory of Ionic interaction and the Theory and Nomogram of Cuban Terrestrial Waters End Members. However, an important step to evaluate the environmental acceptability of these aquifers is the modeling of contaminant transport in order to define the behaviour of the chemical flow injected in any point of the space from defined periods of time. In this paper an analytical 2D advective-dispersive model for constant injection in finite time periods was applied in the modeling of chemical fluxes of conservative substances in the most critical conditions. Results showed that for a timer span of 20 years of constant injection and mixing of produced waters with ground salinized waters some contaminants vanishes at very short distances from the source (less than 10 meters) while others reach the environmental sensitivity threshold values at distances up to 350 meters. Therefore for the projected rates of injection and the designed input concentrations the injection of produced waters in shallow salinized karst aquifers becomes environmentally feasible.